Richard harte



METTE@ STATES PATENT CEErcE.

RICHARD HARTE, OF CROYDON, ENGLAND.

CRYPTOGRAPHIC INSTRUMENT.

SPECIFICATION forming part of Letters Patent N0. 492,677, dated February 28, 1893. Application filed SeptemherSO, 1892. Serial No. 447,367. (No model.)

To all whom, it may concern:

Beit known that I, RICHARD HARTE, journalist, of l Chatsworth Villas, Croydon, in the county of Surrey, England, have invented new and useful Improvements in Cryptographs, of which the following is a full, clear,

and exact description.

My invention relates to an improved cry tograph or instrument for translating communications into and out of cipher in accordance with any arbitrarily selected collocation of letters word or sentence of indefinite length adopted as a key. The instrument comprises two or more similar elements in combination, each element consisting essentially of fixed and movable alphabetical series of letters and corresponding indexes so combined and arranged for operation with regard to each other and capable of such preliminary adjustment with regard to any selected key letter, that the key letter, the letter to be disguised or translated, and the corresponding cipher letter, may be said to be mutually reciprocal inasmuch as from anytwo the third may be found so that the instrument may be used in precisely the samemanner whether for translating a message into or out of cipher. One of the series of letters may comprise more than one complete alphabet. Each element comprises a fixed alphabetical series of letters (which may be termed the normal alphabet) and a movable indexin combination with another index movable therewith as one and with a movable alphabetical series (which may be termed the cipher alphabet-s) and an index which is adjustable with regard to a third fixed alphabet, which may be termed the key alphabet and which bears a constant relation to the first mentioned or normal alphabet, the movable cipher alphabet and the key index last mentioned being constant with regard to each other and moving together for the purpose of being set or adj usted with regard to the fixed normal and key alphabets, so as to determine the relation of the normal and cipher alphabets according to the key letter selected. The movable members of this combination are fitted to work alongside the fixed members and are adjusted with reference thereto by a rectilineal sliding motion. By arranging any number of such elements side by side, a cryptographic instrument is produced which may be conveniently used in connection with a key word or sentence of any length.

Reference is to be had to the accompanying drawings forming part of this specification,

Awherein Figure l is a plan View of the instrument and Fig. 2 is a cross-section,on line 1--1 Fig. l. Fig. 3 shows a detail of construction.

The same letters of reference denote like parts in all the figures.

The drawings illustrate an instrument comprising only five elements, but it will be understood the number is capable of unlimited extension according to the length of the key word or sentence to be adopted, or the same elements may be reset as often as desired to complete the key word or sentence. Each element comprises a stationary strip A bearing the normal alphabet over or Aalongside of which works a sliding index a carried by a sliding strip a working alongside the strip A. Adjacent to this strip a is a fixed strip C and beyond this a sliding strip B bearing two complete cipher alphabets preferably arranged.l consecutively and in inverse order to thenormal alphabet A.

b is the index of the cipher alphabet B. It is made in one with the index a and to avoid liability of mistakes, it is preferably but not necessarily placed out of line with the index a and for the same reason the alphabets A B are printed in different colors. Upon the upper end of the strip B is carried an index c which works over a fixed key alphabet C at the upper part of the instrument and is adj usted with regard thereto according to the key letter selected, and together with cipher alphabet B remains stationary after being so set- Thus B and c move together and are constant with regard to each other while a and b are also constant with regard to each other and are adjustable with regard to A and B respectively, so that the indication given by the index b will vary according to the adjustment of the cipher alphabet B. and B are fitted to slide in grooves in the base board of the instrument and have handles by which they may be easily moved.

It is preferred to construct the instrument The slides a of cardboard by attaching the parallel fixed strips A and C of that material to a base board'D of the same or other solid material so as to leave grooves between the said strips in which the movable strips a and B slide. The upper and lower portions of all the strips are covered by top plates of. cardboard E, F, leavin guncovered the middle portion of the instrument at which the alphabets A B are visie ble and in which spaces theindexes a, b, work.E The movable strips slide beneath these cover. plates and in the upper cover plate E is a seriesofapertures eat-which the key aflphai bets C are visible and in which the indexes c work. The several indexes are preferably at-` tached to their respective strips by a wire staplefofthe form shown in Fig. 3, provided with upwardlyA projectingbends or offsets which can be conveniently grasped betweertf the finger and" thumb for the. purpose of shifting the 'slid-ing strips. The indexes a b, are preferably formed with a gap disclosing the letter indicated and covering the adjacent letters, so as to avoid liability of-error. The i-nstru ment-may be used as follows: Supi pose the name Harte to be selected as the key, the several key indexes c of the five com-` binations of elements composing the instru`l .nent are set to theseveral letters-of that key. word,!as shown. Suppose the word to be translatedinto cipher to be the name Clarkf` vthis may be'done by bringing the several in{ dexes a to` the several letters-of that yword on Ithe normal .alphabets A, as shown, whereby the indexes l) arebrought opposite the .sev. eral letters F, P, R, C, U, on .the .different cipher *alphabets B .which letters .are the ci phers corresponding to the word to be transmitted. To retranslate this cipher. word the recipient having set the indexes c of( this instrumentto the key-word Harte, ybrings the indexes a to the cipherffletters F,A P, R, C, U, on the normal alphabets'Aand reads off the message Clark?9 -on the'` cipher-alphabets B atthe :indexes b.

I claiml. -A cryptograph, or instrument't'or translating communications into or out of cipher, consisting essentially of the combination of a fixed .normal alphabet strip, a movable cipher alphabet strip parallel with and moving. in proximity to the normal alphabet. and provided withan index, a double movable index working over both of said alphabets, andanother fixed-or key alphabet parallel to but not alongside of the normal and ci pheralphabets, and .witlrregard to which key alphabetand to Ithefnormal alphabet the movablev cipher alphabet is adjustable by means of theindex carried by said movable alphabet strip, substantially as specified.

2. A cryptograph,or instrument for translating` communications into or outof cipher, consisting essentially of the combination of a fixed normal alphabet strip, a movable cipher Valphabet strip parallel therewith and Working in proximity thereto and provided with an index, a double movable index working over both of said alphabets, and another fixed or key alphabet parallel to but not alongside of the normal andA cipher alphabets, to which key alphabet and to the normal alphabet the cipher alphabet is adjustable by means of the index 'carriedby the movable cipher alphabet strip, substantial-ly as specified, the key index and key alphabet being visible at an aperture in the instrument frame .removed from the normal and cipherral-phabets Vdirectly used in translating, soas toavoid confusion there with, as described.

. 3. yA cryptographconstructed of acombinaf tion of two or Vmore elements, each element consisting of the combination `off a xed normal alphabet strip, a movable cipher alphabet stri-p parallel therewith andworking in l proximityl'thereto and provided with an' index,va double f movable index .working over .both ot said alphabets, andanotherxed-key alphabet parallel to lbut not alongside ofthe normal cipher alphabets to which key alphabet and to the normal alphabet lthe movable cipheralphabet iszadjustableby `means of lthe index carried-by themovable cipher alphabet strip, substantially as specified.

4. The herein described instrumentfrcon-fv structed of, parallel strips fixed `to a base plate, interm ediate slidin gstrli ps workin gin-grooves alternating with the fixedv strips, :normal and key alphabets carried on:.,the,:fixeds.strips,a

double index. oneach alternatesliding strip, l a doublezci'pher alphabet on the. remaining sliding strips, and-an indexen each off-said cipher alphabet strips as specified.

vThe hereinv ydescribed. instrument constructedof. parallel strips fixedtoabase plate intermediate sliding strips workingingrooves alternating Withthe :fixed stripsnormalrand key alphabets carriedv onthe.fixedstrifpsfa double. index oneach alternatesliding strip having gapsat opposite. sides out of alignment. with each other, a double cipheralphabet onthe remaining slidingvstrips, andan index on each of .said cipher alphabet strips as specified.

Dated this 26th day of August, 1892.

. RICH-ARD HARTE. Witnesses:

A. M.` CLARK, 53 Chancery Lane, LondonPatent Agent.

T. W. KENNARD, 53 Chancery Lane, London, Clerk.

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